Using the imperative form of the verb is totally fine, and it makes the headline feel more active.
The missing article is also a fairly common omission in headlines. That said, if they included it, they would use the US form, so “a union” instead of the British form, “an union.”
The Capitalization Of Each Word Is Annoying But Yes, It’s Grammatically Fine
Except the missing vowels.
Where is there a missing vowel?
My bad, not vowels, english is not my first language. What was the name of at, an, to, etc.?
an is an article and at and to are prepositions
Using the imperative form of the verb is totally fine, and it makes the headline feel more active.
The missing article is also a fairly common omission in headlines. That said, if they included it, they would use the US form, so “a union” instead of the British form, “an union.”